Field of the Invention
The present invention relates to a pneumatic tire with improved noise performance and uneven wear resistance, without deteriorating drainage performance.
Description of the Related Art
As a pneumatic tire with improved wear resistance and drainage performance, Japanese Patent Application Publication No. 2001-206020 describes a pneumatic tire having a tread pattern as shown in FIG. 7. This tire includes, in a tread portion a, five circumferential main grooves b, for example, including outer circumferential main grooves b1 which are disposed most on tread ground-contact ends Te and inner circumferential main grooves b2 which are adjacent to the outer circumferential main grooves b1 axially inwardly with this, outer land portions c1 are formed on axially outer sides of the outer circumferential main grooves b1, inner land portions c2 are formed between the inner and outer circumferential main grooves b1, b2, and center land portions c3 are formed between the inner circumferential main grooves b2 and a central circumferential main groove b3.
In addition, multiple inner lateral grooves h are provided in the inner land portions c2. This divides the inner land portion c2 into multiple circumferentially arranged inner blocks g. The inner lateral grooves h extend in an arc-like manner from the outer circumferential main groove b1 to the inner circumferential main groove b2, while gradually increasing an angle α with respect to an axial line above 30°.
In a tire with such a pattern, however, the uneven wear resistance is not sufficient in the inner blocks g, and further improvement is desired. Note that it is proposed to enhance the uneven wear resistance by reducing a groove width of the inner lateral grooves h to improve rigidity of the inner blocks g. This case, however, results in a disadvantage that the drainage performance deteriorates and wet performance deteriorates.
Hence, an object of the present invention is to provide a pneumatic tire which can enhance uneven wear resistance without deteriorating drainage performance, and contribute to enhancement of noise performance.